DE2633795A1 - ANALYSIS DEVICE FOR MULTI-CYLINDER COMBUSTION ENGINES - Google Patents

Description

COHAUSZ & FLORACK

PATENT ADVOCATE OFFICE D-4 DÜSSELDORF. SCHUMANNSTR, 97

PATENTAN WALTE::

Dipl.-Ing. W. COHÄUSZ · Dipping. W. FLORACK Dipl.-Ing. R. KNAUF · Dr.-Ing., Dipl.-Wirfsch.-Ing. A. GERBER Dipl.-Ing. H. B. COHAUSZ

Applied Power Inc.

TJSA-Menomonee Falls, Wis. 53051 5 July 1976

Anal reader for multi-cylinder internal combustion engines

The invention relates to an analysis device for multi-cylinder internal combustion engines in one embodiment with an electrical ignition device for each cylinder and with means for applying ignition voltage pulses to the igniter in a row.

It is common practice in engine diagnostic equipment to use a signal that from the voltage pulses applied to the engine ignition devices is derived to determine the operation of the test apparatus. For example, one or more ignition devices can be selectively disabled can be set, and by using a counter or other timer device, it is possible to count the number of Ignition pulses to determine which cylinder to any particular one Time is just igniting * It is also known to use such a signal to signal the horizontal line of a cathode ray tube determine which forms part of such a motor diagnostic device. Often it is regardless of the type of test work being performed desirable to terminate the testing process at a point prior to the occurrence of the Start ignition pulse, which is taken into account in the test will. According to US-PS 5,572,103 and 3,573,608 this is achieved by that a signal is derived at the dividing points and this signal is used to generate a pike wave with the same Generate frequency as the appearance frequency of the impulses that by opening and closing the dividing points. This

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System works quite well when the distribution points are readily accessible or when connected to the primary winding at the point at which it is connected to the distribution points, creates a voltage necessary for use in the engine diagnostic device is accessible. However, if inductive taps are used or if, as in the case of electronic ignition, it is often very difficult to make an effortless connection to any point in the system that makes connections to the Distribution points or peaks, it is often necessary to make a connection to the secondary winding of the ignition coil. This creates a signal that roughly indicates the time a voltage has been applied to the igniter, but it doesn't readily an indication of any intermediate point that is in the distance from the ignition pulse by a certain part of the period. Due to the wide changes in engine speed with which such When testing operations need to be performed, it is impossible to use the ignition pulse to generate a square wave of fixed duration and to make them suitable for all engine speeds. It is therefore desirable to have a stress wave like the one that appears at the distributor tips has a certain fixed Has intermediate point that appears at a point in the period that is a relatively constant percentage regardless of the Frequency of appearance of the ignition pulses.

A different problem often arises where the meter is used. It It is necessary to ensure that the counter begins counting at a certain point in the engine cycle. That is why it is common to use the ignition signal applied to a specific engine ignition device to generate a further pulse, which, in turn, is used to ensure that the counter is reset at the time an ignition signal would normally be is applied to the ignition device in question. The problem that arises with this arrangement is that the connection to the Ignition wire to the respective ignition device can run close to one or more other ignition wires, so that a signal

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taken up by ignition cables to other ignition devices can. While it has been suggested an arrangement to prevent it supplying such a reset signal to the counter times other than when an ignition signal is normally to be provided the selected candle is fed, known arrangements have a disadvantage in that when the diagnostic device connected to a motor that is running before power has been turned on to the device, it is possible into a situation at which the counter cannot begin its game at all.

Me invention is with an analyzer for multi-cylinder internal combustion engines in an embodiment with an electrical ignition device for each cylinder, with electrical ignition pulse generating means and means for applying the pulses generated by the pulse generating means Voltage pulses in a sequence to the various ignition devices the analyzer having means for connection with the pulse generating means for deriving therefrom a series of voltage pulses each occurring at about the time a Ignition voltage pulse is applied to one of the ignition devices, also means for generating a cyclically changing voltage this series of voltage pulses with a frequency equal to that of the Ignition pulses so that a full period of itself is cyclical changing voltage occurs between any two such ignition pulses, this voltage being used to determine the function of the test device is used in such a way that a working cycle of the test device in the vicinity of the end of a first half cycle of the cyclically changing voltage is initiated in such a way that the test process is initiated at a time between times, to denön successive ignition pulses appear.

The generation of this cyclically changing voltage is achieved in that a first cyclically changing voltage is derived from the series of ignition pulses with a frequency that is half the frequency with which the © pulses appear, and that from this a ζ \ A cyclically changing voltage is generated with a frequency that is equal to that of the appearance of the impulses. Specially happens

this by using the ignition pulses to generate a series of square waves by using a bistable multivibrator. The bistable multivibrator is every time! then triggered when a Pulse is applied to its input, and the square wave goes continues until the next pulse is received, and when that happens a new square wave of opposite polarity is generated, the continues until the next pulse is received. This square wave voltage has, as previously mentioned, a frequency. which is half that of the appearance of the impulses because only one half period of the square wave appears between any two consecutive pulses. This first square wave voltage goes by an integrator which generates a triangular waveform voltage of the same frequency as the first square wave voltage. Under use to this triangular waveform voltage, it is now possible to easily apply a triangular wave voltage of twice the frequency by passing the triangle waveform voltage through a voltage doubler. This triangle waveform voltage with the Twice the frequency of the original, which is the same frequency as the occurrence of the ignition pulses, can now be differentiated, to generate a square wave voltage at the desired frequency.

The second square wave voltage that has a frequency that is the same that of the appearance of the firing impulses makes it possible because they change their polarity at a point halfway between the appearances the pulses change to control various tester and have a period that is at some point between the appearance of the firing pulses goes out. As discussed above, this is desirable for a variety of testing operations. For example, if the device has a Cathode ray tube contains, the voltage pulses are used directly or indirectly to tilt the cathode ray tube horizontally on which various information to be checked is superimposed, and this information indicates the state of the igniters. For example can the voltage on any selected ignition device, which appears at the time of ignition of the igniter, on the

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and can be used to move the horizontal track around a Deflect amount that indicates this tension. In a so-called "Baradendisplay" will appear on the various ignition devices Tension made visible successively in a sequence, so that during a tilt of the cathode ray tube all voltages that the Accompany the ignition of the successive ignition devices, one in a sequence are made visible one after the other. In other cases, the Cathode ray tube operated so that a number of horizontal Tracks, one on top of the other, are created, with a track for each relevant ignition device is available. Such an arrangement is known from TJS-PS 3,573,608, to which reference has already been made has been. This type of viewing is often called a "Haster" display designated. Regardless of the type of visualization used it is obviously desirable that the start of the track at another point in time when the ignition voltage is applied the ignition device in question is applied. The reason is how in., U.S. Patent 3,575,608 explains that the information observed should be, is the one that appears when the ignition voltage is applied to the Ignition device is applied. Venn the trail doesn't start until the Ignition voltage is applied to the ignition device, it is possible that part of the desired information at the end of the previous track and partly appears at the beginning. By keeping the track ahead of the actual Applying the ignition voltage to the ignition device can begin appears the information to be observed much later than the beginning of the Track. ■ .. "■"

Another application that is done with the Eeehteckwelle tension can, which has been described above, is the function an arrangement to selectively control different ignition devices put out of service. A common way to check the The power of an engine consists in selectively disabling various ignition devices and the effect on the power watch the engine. If the ignition device worked properly Obviously, disabling that particular ignition device results in a decrease in engine speed, and it can ■■. ■ ". ■.; ■■ '■' .;. ■ -" "'■■ ■ - 6 -

observed in any suitable manner, such as on a tachometer. When working with a cathode ray tube, the decrease in the voltage at the connections of the ignition device on the cathode ray tube can be observed. In any event, it is highly desirable that it be possible to determine which igniter is normally operative at any point in time so that it is possible to choose which igniter is being disabled and to know which igniter is being disabled. One method which has been used and which is known from TJS-PS 3 57 ² is to use an electronic pulse counter which has several output stages, the number of which corresponds to the number of cylinders. A voltage appears successively at the various output stages as the counter continues to run as a pole of the application of successive pulses to it. Again, it is desirable that the counter continues to run at a point in time which corresponds to a point in time between successive ignition pulses, so that the voltage appearing at the output terminal, which corresponds to the ignition of a respective ignition device, occurs at a point in time before the point in time at which the Ignition device a voltage is applied. By using the voltage in the manner described, it is possible to have each stage of the pulse counter run at a time which is earlier than the time at which an ignition pulse is normally applied to any ignition device.

Wherever such a pulse counter is used, there are also means provided to ensure that the pulse that is used to ensure the stepping of the pulse count rs at the desired time, is only applied to the ring counter at the desired time. This impulse is usually selected by a connection to a relevant one Ignition device derived. It is possible, as stated above, in connection with this one ignition device, Premdimpuls let develop. In the arrangement according to the invention, the pulse counter is used to detect the application of a pulse from this one to allow the ignition device concerned only at the time when the counter is in a state corresponding to "the time at which

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the igniter would ignite. At all other times, the agents are ¹ to apply a pulse to the counter as a result of a set voltage pulse .Anlegens .One of these igniter except puncture. · ■

The invention is explained in more detail below with reference to the drawings. In the drawings are:

1A and 133 a schematic representation of the apparatus shown in FIG Connection to the ignition devices and the distributor of an electronic ignition system is shown, which is also schematically is shown, and

Figure 2 is a schematic diagram showing various electrical waveforms at different points in the circuit.

In Figs. 1A and 1B, this is the engine diagnostic apparatus with a Automobile ignition system connected, which is shown schematically. at this automobile ignition system, which is schematically connected to a Six-cylinder engine is shown, 10 denotes the usual ignition coil with a low-voltage primary winding 11 and a high-voltage secondary winding 12. The low-voltage primary widening 11 is connected to the Positive pole of the vehicle battery 15 connected via a switch .14, at which can be the normal ignition switch. Esdn current flow from the positive pole of the battery 13 through the primary winding 11 is of a Ignition control unit 16 controlled, in turn by an inductive unit 17, which cooperates with a magnet rotor 18 which has six teeth 19 corresponding to the six cylinders of the motor. For simplicity, the engine diagnostic device is in conjunction with a six-cylinder engine. It goes without saying, however, that the Invention can be used to the same extent in connection with an engine, which has any conventional number of cylinders. The Botor 18 is from Motor driven together with the distributor arm 20 of the distributor 21. The rotor 18 makes one complete revolution for each complete revolution Engine cycle off. Cam 19 of the rotor 18 sit so that they induk- ■ tiν are coupled to the inductive pick-up 17. During the pre

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During each Uocke on the inductive attacker 17, an impulse is generated therein induced and this pulse becomes the input of the ignition control unit 16 sent. The input of the ignition control unit 16 is thus supplied with a series of relatively sharp impulses, one for each Crouch 19 of the rotor 18. The ignition control unit is conventional Form provided as used in capacitive ignition systems is, and it is used to control the function of an electronic switch between the lower terminal of the primary winding 11 and Ground is connected, the Ilasse connection being shown at 24. · Every time one of the squats 19 is in an inductive position to the inductive Tap I7 migrates, the ignition control unit 16 takes effect, to interrupt the circuit that would otherwise be supplied by battery I3 through the ignition switch 14 »the primary winding 11 and the ignition control unit 16 goes to crowd at 24. The consequence of this is that there is an abrupt change in the current flowing through the primary winding, to cause a high voltage to be induced in the secondary winding 12. In this regard, the effect is that of a conventional system similar to working with tips, the main difference being that instead of a mechanical switch an electronic switch is used, which is operated by the inductive Pickup I7 is triggered. The consequence of this is that a sequence of High voltage pulses in the secondary winding 12 is induced. The upper connection of the secondary winding 12 is via a conductor 25 with connected to the rotor 20 of the distributor 21. The rotor 20 is in turn for the production of a conductive connection with six distributor contacts 26 set up, one for each cylinder of the engine. These distributor contacts are evenly arranged around the distributor and are connected to six ignition devices 30-55, specifically called spark plugs are shown. As the distributor rotor 20 moves into a conductive position with any contact 26, an ignition voltage is generated applied to that of the spark plugs JO to 55 to which the relevant Contact is connected. The rotor 18 of the ignition control unit and the distributor rotor are driven by the motor and are arranged so that the high voltage pulses appearing in the secondary winding 12 occur approximately at the times when the distributor rotor 20 is on

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the contacts 26 attacks. With the turning of the distributor rotor, the is driven by the engine, so an ignition voltage is controllable applied to candles 30 to 35 in a Bige. It goes without saying; that each of these spark plugs 30 to 35 is assigned to a different cylinder is. While according to the illustration, the spark plugs in a continuous Row are arranged, it goes without saying that they are in the cylinders are assigned in such a way that the desired firing order arises. Further, while specifically showing spark plugs, understand it is understood that other forms of igniter may be used.

In the engine diagnostic apparatus, 40 denotes a ring counter * This Ring counter has a number of stages that are equal in number to the maximum number of cylinders of any engine being tested will. For the sake of simplicity, the ring counter is shown as having six stages, numbered 1 through 6, around the Seohs cylinder engine to correspond to that referred to above

is. It should be understood, however, that normally the ring counter is eight Has stages so that the device can be set up to handle the States of eight-cylinder internal combustion engines to dtignos ti decorate.

The ring counter 40 is in principle the same as the ring counter 35 off U.S. Patent 3,572,105. Such ring counters are somewhat conventional, and for further details of a typical ring counter, see this Art, reference is made to US Pat. No. 3,572,10J. The ring counter 40 has a normal input terminal 41 'to which pulses are applied to to let the counters run from one level to the other. The ring counter has a reset terminal 42 which is used to set the ring counter reset and cause him to repeat his work cycle. Furthermore, an auxiliary reset connection 43 is provided, which, as still will have to be explained, receives a pulse in a certain phase of the engine operation to ensure that the ring counter is "in progress" with the engine remains.

The ring counter has six output connections, one for each of the stages 1 to 6, and these. Output connections are connected to switch contacts

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those designated by the reference numerals 45 "to 50". Furthermore have levels 4 and 6 auxiliary input connections - 52 and 53. Bs understands that if an eight-stage counter were used, an auxiliary connection in connection with stage 8 would also be available. if the "device would be used accordingly to two-cylinder engines check, there would be an auxiliary input connection in the second stage.

A switch tongue is assigned to each of the switch contacts 45 to 50, and these switch tongues are designated 54 to 59. It understands that any of the switch reeds 54 Ws 59 are selectively attached to the associated Contact of contacts 45 to 50 can attack. The switch prongs 54 to 59 are all connected to a common conductor 62, and if any of the switch tongues 54 to 59 on the associated contact attacks, the output of the stage in question, which is assigned to this connection, is connected to conductor 62.

Auxiliary output terminals 52 and 55 are connected to contacts 65 and 66 of a switch 67, the switch tongue of which is moved into engagement with contact 65 or 66 , depending on the number of cylinders in the engine that are currently being tested. The switch 6 "J is in turn connected by conductors 68 and 69 to a capacitor 70 and to the reset terminal 42.

In operation, pulses are applied to the input terminal 4I, to be described later, one pulse being applied each time an ignition voltage is applied to one of the ignition devices. The series of pulses applied to the input terminal 41 cause the ring counter 40 to progressively advance from one stage to the other, and this causes an output voltage to appear successively on the switch contacts 45 to 50 (when a six cylinder engine is being tested). When the level corresponding to the maximum number of cylinders in the engine being tested takes effect, the voltage appearing on output terminal 52 or 55 is applied to reset the ring counter. In the switch position shown, the switch tongue of the holder 67 is connected to the contact 66 , which is with

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is connected to the auxiliary terminal 52, which is assigned to the fourth stage is »Under the conditions shown, the device is arranged to be used in "conjunction with a four-cylinder engine." will. When an output voltage appears at stage 4, a voltage from auxiliary output terminal 52 to contact 66 of switch 67 and through conductors 68 and 69 and capacitor 70 to the ■ Reset connection / created. Under these conditions the / 42 Ring counter 40 is therefore reset after it has been in Activity has been. Levels 5 and 6 are therefore disabled. If, on the other hand, the switch is brought into contact with the contact 6-5 with its tongue 67, the ring counter continues to run * until a voltage is applied is applied to the sixth stage auxiliary output terminal 53. Under these conditions, the voltage from the auxiliary output terminal 53 becomes through contact 65, the switch tongue of switch 67 and the conductors 68, 69 and capacitor 70 are applied to reset terminal 42 to to cause a reset of the counter when it has gone through six operating stages.

As explained above, pulses are applied to the input terminal 41 is applied every time an ignition pulse is applied to one of the ignition devices is created. In the case of a six cylinder engine, there will be six pulses on terminal 4I for each complete stroke of the engine created. Where it is possible to connect the primary winding 11, and where the signal from the. Primary winding is of such a type that it is useful for this purpose, is the signal diverted from the primary winding? tet · A clamp connector 75 is connected to one terminal of the primary winding 11 appropriate. This direct connector provides a direct conductive connection. connection to the primary winding, and it can be for example act a tension clamp. The connector 75 is through a conductor 76 connected to a terminal 78 of a switch 79, the switch tongue connected to the input of a square wave generator 80, Die-r this square wave generator preferably has a filter for filtering out any high frequency extraneous components of the primary voltage and a Schmitt trigger for converting the pulses into a square wave voltage of essentially constant amplitude, the frequency of which is the same is the frequency of appearance of the ignition pulses. The Schmidt trigger works

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fet so that half of the square wave is delivered during the time becomes, · during which the ignition control unit 16 has a conductive ¥ eg forms to the primary winding 11, while the other half is gf-supplied, while the ignition control blocks a current flow through the primary winding 11. The output of the square wave generator is through a Condenser 81 conducted, which acts so that a series of sharp pulses relatively short peasants emerge. These pulses are sent to the terminal 4-1 is applied, and whenever a negative pulse is applied to the. Terminal 41 is applied, the counter moves from one stage to another moved on. The counter is preferably by some means such as a diode, not shown, is provided to block the positive pulses coming from capacitor 81. So the counter is running one stage after the other, each time the ignition control unit takes effect, to allow a current to flow through the primary winding to allow. An important feature of the invention is that the stage continues at the time the ignition control unit 16 is on Current is allowed to flow through the primary winding rather than at the time when current is interrupted through the primary winding. In other words, the counter is incremented at a time equal to the "tips closed" position of a conventional system is equivalent to. Furthermore, the counter is switched on by the primary winding 11 before the circuit is opened, and this leads to the ignition of the Spark plug assigned to this level. The ring counter becomes a / Lso actually advanced before the time at which the ignition pulse for the associated cylinder occurs. For example, the counter moves up into stage 2 before the ignition pulse is applied to the ignition device that corresponds to this level. In other words, a voltage is applied to the output terminal 46 of stage 2 before a Voltage is applied to the igniter that corresponds to this stage.

In the above explanation, it has been assumed that it is possible is to take the signal from the primary winding that is required to advance the counter 40. Unfortunately, it isn't always possible, as has been explained above. In certain cases, in particular with electronic ignition systems, it is impossible to have one

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establish a conductive connection to the primary winding, because the entire Ignition system is housed in such a way that an effortless Access to the connections of the primary windings is prevented. at different types of electronic ignition systems is also tending to occur the signal from the primary winding to take various forms, and it is not always possible to be sure that the device is compatible with the Square wave generator 80 for generating a waveform from: one such Signal is suitable for use to advance the counter suitable is. The invention is particularly concerned with this situation. and it is with receiving a signal from the output of the secondary winding which can be used to move the counter further, and that has a definable intermediate point such that this Intermediate point "can be used to define the time, too." which the counter is advanced. As stated above, it is desirable to advance the counter ahead of the time at which the firing pulse is applied to the igniter.

In FIG. 1B, 85 designates a quickly detachable connector which can be capacitive and which is connected to the conductor 25 which leads from the non-grounded connection of the high-voltage secondary winding 12 of the ignition coil 10. The connector 85 is through A shielded cable 87 is connected to the input of an amplifier stage 88 as shown in Fig. 1A. The amplifier stage 88 is designed to have a relatively high impedance input and a relatively low impedance output As can be seen, the capacitor 89 is connected between the capacitive connector 85 and a ground connection 90. A certain part of the voltage that appears at the terminal of the secondary winding 12 that is not connected to ground therefore appears at the capacitor 89, which is connected to the input of the amplifier 88. The amplifier stage 88 has a field effect transistor 92. The upper e connection of the capacitor 89 is connected to the gate of this field effect transistor. This gate is normally kept at a certain voltage by connecting it to the connection between two resistors 9J> xmd. 94 is connected between a +15 volt source

and the ground connection 90 are connected. The drain of field effect transistor 92 is connected to the +15 VoIt source through resistor 95 and the source electrode is connected to ground through resistor 96. The voltage at the resistor J6, which is present between the source electrode and the cash register, is applied to the input terminal of a further amplifier 100 through conductors 97 * 98 and a capacitor ^. This amplifier 100 is connected to a +15 volt power source by conductor 101 and connected to Hasse by conductor 102. The output of the amplifier 100 is applied through a diode 105 to a capacitor 105 which is periodically charged to a value which corresponds to the magnitude of the secondary voltage which is picked up by the connector 85. Because the output stage of the amplifier 100 has a relatively low impedance in the conductive state when the transistor

110 conducts is the time constant of the circuit from the +15 VoIt voltage source due to the diode and the capacitor extremely low to allow fast charging of the capacitor I05 to a voltage, which is proportional to the voltage pulse of the secondary voltage. The way of working ii ° r amplifiers 88 and 100 for charging the capacitor 105 already described elsewhere in connection with a similar circuit been.

As suggested elsewhere, funds are provided to periodically discharge the capacitor 105. These means have the form of an n-p-n transistor 110 which, via its mode 111, is parallel to the capacitor 105 is switched. As can be seen, it is the emission electrode of transistor 110 at 112 connected to ground. So it lies It is readily apparent that when transistor 110 conducts there is a discharge path from the top of capacitor 105 through the diode

111 and transistor 110 is formed to ground. Until the transistor 110 becomes conductive, however, the capacitor 105 has no readily available charging path. As can be seen, the capacitor is 105 connected to the output of the amplifier 100 via a diode 103, which effectively blocks any discharge of capacitor 105 through amplifier 100, while capacitor I05 »as explained is connected to the input efce of an amplifier 115, this is

Amplifier chosen "that" it "acts as an isolating amplifier" around someone to prevent significant discharge of the charge on the capacitor 10 $ * - change. So while the capacitor 105 very quickly to a value of V. is charged »which corresponds to the incoming signal, the voltage remains at the capacitor essentially to this value until the transistor 110 is turned on.

The conduction of transistor 110 is controlled by a timer circuit 116 controlled with two stages 117 and ti8. These two timer levels correspond to the two timer levels already used elsewhere have been proposed. Generally, the first timer level is for this intended to provide a timing that is very short, for example 100 microseconds »This timer is used to run the transistor 110 at the end of this very short timing. The second timer 118 is provided for the purpose of ensuring that the capacitor 105, if it has been discharged due to the function of the first timer circuit, in connection with the transistor 110, for a considerable amount Remains discharged for a period of time in order to largely rule out the possibility of that the capacitor is accidentally recharged, as a result of, for example, any unwanted signal that occurs between the two Zurich pulses appear that are to be measured.

The timer circuit is controlled by a connection 120 which leads away from an output connection of an intermediate stage of the amplifier 100, so that the " ¹ '" preferably "" is a multi-stage amplifier The conductor 120 is connected to the input terminal 123 of the timer circuit II7 through an amplifier 121 and a capacitor T22. The Z'eTtg'eier 117 'ί ¥ ΐ preferably "a" typical linear integrated circuit timer ¹ "of the ^rrV Ty-p'eV' diVars a 555'er '^; timer circuit on the market" - 'eTrhETtlich' is ⁵ . A "" typical '' timer of this type is the 555 "'^^^^^^""' ^! ^^! ^"'CorporVtibn *. "''!? ^ It goes without saying that other corresponding characters" ^ tgei3ervör ^r i ^c htüngen 'can be used. The time period "of the" circle "" is "determined by a capacitor" ^ 6 connected between the intlade- "and Schweileriwer'tanschlü ^" 127 "UrId" 128 and ground. The lower connection of the capacitor 126 is with a

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• Ground conductor 129 connected, which is connected to the cash register at 1JO. In practice, conductor 129 can be the Hasse-applied housing of the timer circuit. The discharge and threshold value connections 127 and 128 are also connected to a + 15-tolt current connector via a resistor 1 * 1. The Hückstellanschlu.3 1JJ- and the StronanschluiJ 1J / ¹ are both interconnected and connected to this + 15-ToIt tr connector. The ground terminal 135 is connected to the ground conductor 129 via a conductor 156. The control voltage terminal 158 of the timer II7 is. connected via a capacitor 139 to the same ITasselleitung 129. "The puncture of the timer 117 consists in generating a sequence of relatively short timing periods which are initiated at the beginning of each voltage pulse that is taken from the secondary winding of the ignition coil 12 and at which the timing period of the timer 118 is initiated explain its vard, initiating the timing period of timer 118 causes transistor 110 to turn on to discharge capacitor 105. Transistor 110 is held conductive during the timing period of timer 118 which, as noted above, is significantly longer than that of the timer 117 is.

The timer 118 is essentially the same as the timer 117 except for the longer timing period determined by the timer capacitor 143. For example, the timer II7, the timer 118 is a 555 linear integrated circuit, and it can be the Type act, which ^he sold Fdnheit Signetics Corporation as the 555th The connections I42, 144 »145» 146, 147 »149 and 150 correspond in their function to the connections 123, 127, 126, 133» 154 »135 and 138 of the unit 117 · The main difference between the two timers is the difference in the fourth of timer capacitors 126 and 143 and resistors 13I and 145 * I * ^1, a typical case a 0.001 microfarad capacitor is used for capacitor 126 and resistor 13I has a resistance of 100K ohms, while a 0.01 microfarad capacitor is used for the capacitor 143 together with the resistor 145 with 220 KOhm. In other words, the EC constant of the timer 118 is 22 times that of the timer 117.For this reason, the timer II7 has

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ORIGINAL INSPECTED

example mentioned a timing period of about 100 microseconds while the timer 118 has a timing period of approximately 2.5 milliseconds Has. - - "-_.-" "." "" ..-- ~ ■ "'

The output terminal 14P "of the timer 117 is connected to the input terminal 142 of the timer 118 through a capacitor I4I. The function of the capacitor I4I consists in the timing pulses transmitted by the Timers 117 are generated, to differentiate, and to generate a sequence of positive and negative peaks. The positive peaks will be shunted through the zener diode, and the negative spikes are held at the Zener breakdown voltage, e.g. ten YoIt. This means that the U input terminal I42 is a series of negative ones Peaks supplied - each negative peak at the end of one of the pulses from timer 117; corresponding. The effect of this impulse is that a positive pulse on output terminal / timer 118 on / 153 and this positive pulse continues for the duration of timer 118 which, as mentioned above, is 2.5 milliseconds can. The output terminal 153 of the timer 118 is through the Conductor 156 and a resistor 157 sun the control electrode of the transistor 110 connected. The appearance of a positive pulse at the output terminal 153 of the timer 118 thus results in the voltage at the control electrode of transistor 110 is increased sufficiently to to cause the transistor to turn on. That leads to manufacture an unloading path for the capacitor IO5 »as in another place has been explained. The voltage across capacitor 105 is promptly noticed a very low value and is held at this value for as long as the transistor 110 is kept conductive. As mentioned above, there is the task of the timer 118 is to keep the transistor 110 conductive for a period of time long enough to allow a To wipe most of the time between firing two spark plugs, if the engine is running at a relatively low speed, but sufficient in short, that when the engine is running at its normal maximum Drteahl the timing period is shorter than the timing period between firing two spark plugs is. The purpose is to minimize the likelihood that capacitor 105 will accidentally break through Transition voltage is charged as explained above.

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The result of the above described in connection with the capacitor 105 Circles is that every time a high voltage pulse is generated by the "connector 85" in the secondary winding 12 as a result High-voltage pulse is received, the capacitor 105 is charged to a ¥ ert, the size of which corresponds to that of this voltage, and then discharged after a "certain period of time. Further it is kept discharged for a longer period of time. The result is that at the input to amplifier 115 a train of square wave voltage pulses appear, the duration of which is constant and the size of the voltage pulse received by connector 85. Regardless of how short is the voltage pulse that has been generated in the secondary winding, so the voltage across capacitor 105 is maintained for a fixed period of time. As discussed above, the amplifier 115 is designed to act as an isolating amplifier to any significant To prevent discharge of the charge on the capacitor 105. The amplifier is with the same. +15 volt voltage source such as amplifier 100 is connected. The output of the amplifier is through a diode 160 with the resistor a potentiometer 161 connected, the lower terminal of which is connected to ground and which has a movable slide 162. It can be seen that, depending on the position of the slide 162, a selected part of the voltage appearing at the output of the amplifier 115 between the Slide 162 and mass appears. This tension is in turn over a Capacitor I63 applied to a vertical amplifier I64, its output terminals again through conductors I65 and 166 with the vertical plates 167 of a cathode ray oscilloscope 168 shown in Fig. is shown. The cathode ray oscilloscope is in a conventional form is provided and has a cathode ray tube, the usual fluorescent screen 170, horizontal baffles 172, the vertical Baffles I67 mentioned above, an accelerating anode 174 »a grid 175» a control grid I76 and one Has cathode 177. The cathode is provided with some known means of heating it, and various voltages are applied to the various electrodes through a power connector 173, these details of which are unimportant as far as the invention is concerned is. The operation of the cathode ray tube is conventional, except for the manner in which the voltages are applied to the horizontal

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- and vertical electrodes can be controlled. .

In operating such a cathode ray tube as an oscilloscope, it is common practice to apply a sawtooth voltage between the horizontal plates 172 so that the cathode ray is moved horizontally from one side of the screen 170 to the other at a frequency which depends on the frequency of the sawtooth voltage. The from capacitor 105 through. Voltage applied to isolation amplifier 115 »^ ^en " vertical amplifier I64 and conductors 165 and 166 to vertical deflection plates I67 causes the beam to deflect vertically by an amount and at a time dependent on the charge on capacitor 105. The above mentioned, the size of this charge depends on the size of the secondary voltage pulse of the ignition coil 10.

While the apparatus described above forms part of the invention, it is not directly concerned with the novel features of the invention. Referring to the inventive features relating to the device described above, 185 denotes a conventional bistable multivibrator of an embodiment which, when triggered by the application of an input pulse to it, assumes one of two conductive states and maintains this state until a second pulse is received and then it takes on its other conductive state and remains in that state until a third pulse is received. When successive pulses are applied to such a multivibrator, the output of the multivibrator is as a square wave, its length. each half cycle depends on the time between two successive pulses. The pulses applied to the input of the bistable multivibrator 185 are picked up by an OD3R gate circuit, which consists of two diodes 186 and -T8.7, which are connected to one another at a point marked with the letter B. Whenever a Spannug is applied to one of the diodes 186 or 187, the voltage appears at point B. The diode 186 is ^to the timer 118 is connected to the output terminal 153 through the conductor ^ I56. The diode I87 is connected to the output terminal 140 of the first timer 117 through a conductor I89. As explained above, the timer II7 generates relatively short pulses, for example pulses with a duration of 100 microseconds.

7 0 98 0 * 7/0 29 T ^

'the. The timer 118, on the other hand, generates relatively long pulses which. ■ have a duration of 2.5 milliseconds. In the? the CD "H gate circuit · i-.in-" is set, which consists of the diodes 186 and ICJ br, a voltage pulse appears at point B, beginning at the beginning of the voltage pulse at the output 140 of the timer 117 »and continuing, until the output pulse at terminal 153 of timer 113 ends. The reason the ODjVR gate is used and the outputs from both timers 117 and 118 are used is that if only the output from timer 117 were used, it would be possible for "to agree." Transitional conditions two short pulses appear one after the other. The effect of such multiple pulses would interfere with the proper operation of the multivibrator. On the other hand, if only one output pulse from timer 118 was the one on which one relied, the voltage pulse at point B would not start until the timing period of timer 117 has ended, which, as explained above, initiates the timing period of timer 118 after the timing period of timer 117. By using the outputs of both timers, it is ensured that there is only one pulse for each secondary signal , which is generated, and that this pulse begins at the time when the secondary pulse for the first once appears as shown by the peak in curve A in FIG. In other words, the pulses have the form shown in waveform B in FIG. The first pulse thus begins at time H _n f and the second pulse begins at time T2, etc. yj assuming the timing periods given above for timers 117 and 118, each pulse has a duration of 2.6 milliseconds, and this Number represents the combined timing periods of timers 117 and 118. Also note that pulses 195 are all of uniform height, despite the fact that in waveform A in FIG its somewhat smaller size than the secondary voltage pulses associated with the other spark plugs. The uniformity in the amplitude of the pulses 155 is due to the fact that the size of these pulses is determined by the constants of the timing circuits 117 and 118 and not

709807/0207

- 21 ORIGINAL INSPECTED

is determined by the magnitude of the secondary trigger voltage applied to the Input of amplifier 88 is applied.

The voltage inputs appearing at point B are applied to a resistor 196 applied, which is connected between the terminal B and ground is. in parallel with resistor I96 is a relatively small capacitor switched, to shunt any faulty high frequency signals forward that may be present at port B. The voltage at resistor I96 is connected to the input of the through a resistor I98 bistable multivibrator applied. To the input connections of the abisbable Multivibrators in parallel with resistor I96 and capacitor is,. A Zener diode 199 and a further diode 200 are connected. A Capacitor 20β is. connected between the Zener diode 199 and the diode 200. The task of the Zener diode 199 is to limit the size of the positive voltage pulses to a certain value, the corresponds to the Zener breakdown voltage of the diode 197. The condenser 205 differentiates the pulses applied to the bistable multivibrator 185. The function of diode 200 is to shunt the negative components of the differentiated signal. That The result is that a sequence of positive pulses that are refetiv free of there are any externally dissolving intoxication caused by the bistable Multivibrator 185 can be applied to cause it to generate a train of voltage pulses, each at the beginning of the beginning one of the pulses 195 begins and at the beginning of the next pulse 195 is ended. The result is a waveform that appears at C in Fig. is shown. As is readily apparent, this waveform is a pike-corner wave with alternating positive and negative half-periods, TiOH at each half cycle in the length of the period between two successive pulses 195 corresponds. In other words, the C in The square wave shown in Fig. 2 is a square wave having a frequency of half the frequency of the pulses of the secondary ignition pulses.

The output of the multivibrator I85 is connected to connection C via a Resistor 201 applied * The connection C in turn is connected to the input terminal 202 of a functional amplifier 203 connected, a

709807/029 ^

Output terminal 204 has. The function amplifier 203 is a high-performance function amplifier with a high open-circuit gain factor. A typical amplifier of this type is sold as a function amplifier / U A.74I. The amplifier 203 is connected so that it acts as an integrator, having a feedback connection consisting of a resistor 206 and a parallel capacitor 207 between the output terminal 204 of the amplifier and the singing terminal 202. The other input terminal 208 is connected to ground via a resistor 209, as is the output terminal which is connected to ground of the multivibrator 185 · The positive and the negative current connection of the functional amplifier are with a + 15-Yolt-Qaelle and with a -15 Yolt Qizelle connected. As a result of the way the functional amplifier is connected, it works to integrate the voltage appearing at point C to produce a waveform at connection D. which corresponds to that indicated as waveform D in FIG. 2. ¥ ie seen increases during the first positive half cycle of waveform C the voltage at the connection D constant. It reaches its maximum on the last half of this period Waveform. D. During the next negative half cycle of the waveform G, the voltage output at point D is constantly decreasing, which is an integration of a negative wave. This continues until the end of the negative half cycle is reached, at which time it increases the output at point D continues to increase in value. The result of all of this is that a triangle waveform arises and has that waveform again the same frequency as that of the square wave at point C. appears. Again, this waveform has a frequency half that of that of impulses 195

The current at connection D goes through a capacitor 210 of relatively large capacitance. The effect of this is that the DC component is eliminated so that the resulting current is evenly around a center line at ground voltage. The voltage thus appearing at connection 211 is a voltage which has positive peaks above a center line of ground 205 u ¹¹ ^. has negative peaks below this mass, with the positive and negative peaks of equal amplitude. With others

- 23 -

In words, the waveform is symmetrical about a baseline 205 at ground voltage. So the part of the wave between points A and C is' positive, that between C and e is negative, that between e and g is positive USW * The positive parts of the current go through a diode 212 to a point E. The negative peaks pass through an H diode 21J, a resistor 214 and a conductor 215 to the input terminal 216 of an amplifier 217 which is connected to function as an inverter. The amplifier 217, like the amplifier 20J, is a function amplifier commonly referred to as an amplifier uA741 ". In this case, however, there is a feedback connection between the output terminal 218 and the singing terminal 216, which includes a resistor 219, and there are others Connections are provided so that the amplifier acts as an inverter rather than an integrator as is the case with amplifier 2OJ. Amplifier 217 is provided with conventional connections of its power connections to a +15 volt source and a -15 volt source. The output of amplifier 217 in Prom, an inversion of the negative parts of the current η of junction D, is applied through diode 222 to point B. The result of adding the components passed through rectifier 212 and inverter 217 is a current having a waveform shown as waveform Ξ in Pig. 2. As can be seen, the part determined waveform D between points a and c has been passed through rectifier 212 without any appreciable change in its nature. The negative part of waveform D between points c and e has been inverted so that it is now positive, with negative point d now being the most positive part of that part of waveform S concerned. The result is a triangular waveform current with twice the frequency of waveform D according to FIG. 2. Furthermore, points a ¹ , CJ-, e ¹ , g 'result from this, which mark changes in the voltage curve and which ■ between the ignition pulses T1_, 12- , TJ and T4 _Q and so on. Further, these intermediate points lie approximately in the M tte between the ignition pulses, -As that also the felling would be if the device would be connected ^r stems to the points of a conventional Zünds3 and closing of the tips would be used to form reference points.

^ s is desirable in connection with the operation of much of the equipment, to have a hexagonal wave voltage. TJm the at 3 in Fig. 2

709807/0297

showed current in a rectangular wave voltage to convert the current is conducted at the point 3 by a differentiator * This takes the form of p-.nes further amplifier 225 whose ^r ingangsanschluB is connected to a <ru point via a resistor 223 and-a capacitor 224th The amplifier 225 corresponds to the amplifiers 2CJ and 217 in that it is a functional amplifier sold on the market as an amplifier uij.7 ^ 1. Like the other amplifier, its current connections are connected to a +15 volt power source and to a 15 volt source. In this case the amplifier is connected in such a way that, together with the capacitor 224 in series with the input terminal, the amplifier acts so that the current appearing at point E is differentiated. A feedback connection consisting of a resistor 227 is connected between the output terminals and the input terminals of the amplifier. A consequence of the differentiation is that the parts of the waveform E which rise, like the parts between a 'and b ¹ , are between c ¹ and d ¹ and between e ¹ and -f ^{1 become} positive peaks of a square wave, while the parts that fall, like the parts of waveform E between b ¹ and 6c ¹ , between d ^f and e ¹ and between f ¹ and g ¹ negative peaks will.

The output of amplifier 225 is connected to the input of another amplifier 23O connected, which, like amplifiers 205, 217 and 225, is a functional amplifier is how he sold on the market as an amplifier uA74 "1 will. The amplifier 23O is with its power connections a +15 volt source and connected to a +15 volt source. His hate connection is also connected to ground through resistor 232. Further is a feedback connection between the output connector and the input port to which an adversary 234 belongs. Of the Function amplifier is connected in such a way that it acts as an amplifier high Gain factor acts to get a more sharply defined square wave output. This output appears at connection F, and the output is shown as waveform F in FIG. How to can be seen, the waveform is in the form of a square wave with alternating negative and positive half-periods essentially the same Width, where the frequency of the square wave is the same as the Frecp. dance of Is firing pulses shown in waveform A. Us is with this Waveform now possible, sharply defined points between the ignition pulse

- 25 -

70 98 07/0297

BAD ORJGfNAL

to get sen. These points are represented by points a ", c", e ", etc. designated.

This square wave voltage can be used in various ways, to control a test process in which one function at a time between igniting any two spark plugs. In the present example, the voltage appearing at connection P is passed through a conductor 235 to a second switch contact 237 of switch 79 (Fig. 1B), referred to above has been. As will be remembered, the switch tongue is that switch connected to the input of a square wave generator 80 having a Filter and means for generating a sharp square wave, for example a Schmitt trigger. The output of the square wave generator 80 is connected via a capacitor 81, which is the output of the square wave generator differentiates by a sequence of negative Provide pulses at the Singangsan connections 4I of the ring counter 40.

The operation of the ring counter is the same as above has been described. In other words, connect where possible with the primary winding 11 and where the nature of the primary signal is appropriate for the purpose, it is possible that the signal from the Primary winding coming from connector 75 for controlling the square wave generation tor in the manner described above. In in this case the switch tongue 79 is in its lower position in attack at contact 78. However, if it is not possible to use the primary signal, either because the connection of the primary winding is inaccessible or because the type of primary weighing current to use is unsuitable for controlling the square wave generator 80, the circuit according to the invention provides means for generating a rectangular wave from the high voltage pulses taken from the secondary winding be, with the same frequency \ d.e the pulses in front, so that the end of the first half period of each period of the square wave at one Point occurs between the ignition pulses. That makes it possible for different ones Initiate operations at a point between firing pulses as described above. As described above, the counter

is advanced from one stage to another at the time a negative pulse is applied to the 2-input terminal 41, this pulse being supplied by the Heehteck wave generator 80 at a time prior to. Ignition of the "relevant ignition device, the operation of which is to be checked. If the gate direction according to the invention is used, the negative pulse, which advances the counter, appears at points a", c ", e ⁿ , g" etc. In other words, the counter is switched from one stage to the other at a time approximately in the middle between successive ignition pulses.

The counter 40 is used to perform various functions. The first of these functions is that of the horizontal plates 172 of the cathode ray oscilloscope to regulate the voltage applied. The voltage applied to these plates comes from the output of a horizontal amplifier 240 which is of conventional construction like them usually in connection with such cathode ray oscilloscopes is used. This horizontal amplifier 240 is from a saw tooth generator 241, which, as usual with cathode ray oscilloscopes, A sawtooth waveform is generated which in turn is amplified by the horizontal amplifier 240 and sent to the horizontal deflection electrodes 172 is applied. As the sawtooth wave increases in size, the cathode ray tube beam is gradually deflected from side to side. When the sawtooth waveform is at its maximum Reaches its initial value at the end of each of its periods falls, the beam quickly returns to its original position. In practice, a masking mechanism is used to prevent that the ray becomes visible as it returns to its original starting position. However, such a fade-out mechanism does not form Part of the invention and because it is known it is not described here.

So that the voltages applied to the vertical electrodes 167 am To apply the correct part of the tilt of the beam, it is necessary to trigger the sawtooth generator with a signal that has a timing relationship to the signal that is measured, which in the present case

-27 - "

709807/029?

: - 27 -

Play is shown as the voltage on secondary winding 12. In the present example, the output of the last stage of the ring counter 40 is used for this purpose. As has already been explained above, the switch 67 is moved into engagement either with the contact 65 or with the contact 66, depending on whether the machine to be tested is a six-cylinder engine or a four-cylinder engine. The net result "is that prior to the normal application of a firing pulse to the firing device of the last cylinder in the firing sequence, a voltage pulse appears on conductor 68. This voltage pulse has been described above as being used to reset the ring counter and generate a new one However, conductor, 68 is also connected by conductor 245 to the input terminal of sawtooth generator 241. The waveform appearing on conductor 68 at point G showing the connection between conductors 69 and 243 is shown in FIG represented by the waveform labeled with the letter G. As can be seen, this waveform remains at a constant value until a point corresponding to point eS of the waveform - ¥ is reached, which is a point immediately before the point in time to which the fourth cylinder receives an ignition voltage, at which point voltage G drops abruptly and stays low at a new low en value until point g "is reached, which, as can be seen from waveform A, is a point after the ignition of the igniter of the fourth cylinder. The sawtooth generator is designed so that when a negative voltage of the type just described in connection with waveform G is applied, the period of the sawtooth generator is initiated. -

Where, as shown in the example according to the drawing, the ignition pulses shown on a "parade" display, the sawtooth generator increases its voltage output throughout the cycle of the engine. In a "parade" display are the outputs of successive ignition devices one at a time in a continuous tipping of the track over shown across the screen of the cathode ray tube. Such a "parade" display is desirable for certain test purposes because it enables the level of successive secondary voltage pulses to be compared easily light. For example, if any voltage pulse is relatively low indicates a malfunction of the ignition device. For example can that mean for the 3? all one spark plug that the spark plug splits

70980 7/029? '" ^2ß " ·

due to the accumulation of conductive IlaV.rial such as carbon ε, η of the spark plug electrode partly short-circuited ict. In a so-called "parade" display, the Gügsi.z demolished lie, as stated above i '<^ t, ω point g ", and it continues until this point is reached again. At this point, it takes effect üä ₀ tooth generator, so that the voltage drops to full and starts again from ε-tcigfcn.

¹ Hs, however, it can be stated that 3 the jrerioäe of the sawtooth waveform, at a. The point between the points at which the fourth and first igniters are ignited begins. ) * s it is ε.1εο possible to observe the complete voltage pulse, which originates from the ignition of the ignition device for the first cylinder. \ io as the Es.gezahngenerators starts at certain known Cystemen, the period at the time of Spannungsiiapulses, appear a part of the information that is observed on ünde one track and the beginning of another track. In the invention, however, the horizontal track begins before the ignition voltage is applied to the ignition device, so that it is possible to observe the complete secondary voltage pulse without interruption.

Another aspect of the upward counter Δ0 is to control the selective external function of various ignition devices. As mentioned above, one of the most important methods of testing an internal combustion engine is to selectively disable the ignition devices of different cylinders and then observe the effect on the engine running of the disabling of that ignition device. This process is repeated until each igniter has been disabled. In certain cases it is also desirable to disable groups of ignition devices at the same time. Such a test method is described in US Pat. No. 5,572,103. As stated therein, it is desirable that the ignition device for a particular cylinder be disabled prior to the time at which an ignition voltage is normally applied to that ignition device.

Referring to Fig. 1B, it has been pointed out above that with. the application of successive impulses to the 2 input connection 4-1 of the

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07/0297

BATH ORIGINAL

Counter 40 a voltage - successively - appears at the output terminals of the various stages which are connected to the switch terminals 45 ″ to 50. Depending on which of the switches 54 to 59 is closed, the voltage of any of these stages is applied to the conductor 62. For purposes of illustration, switch tongue 55 is shown in attack on switch contact-46, so that whenever an output voltage appears at stage 2, which corresponds to cylinder # 2, that output voltage is applied to conductor 62. As for all others time is no voltage applied -._ the conductor 62, the waveform produced when ^the. switch tongue 55 is closed, as shown by the waveform H, the "strength in!. 2 is shown. This represents the voltage across the connection H in I ¹ Xg. 1B appears. Referring to waveform H in FIG. 2, it can be seen that the voltage level remains relatively low until point 244 is reached. At this time, the voltage jumps abruptly. Point 244 corresponds to point a in waveform D. In other words, point 244 appears at a point between 4th firing pulses from cylinders Fr. 1 and Ur. 2. The voltage increase that occurs at point 244 continues at a steady rate until a point 245 is reached, at which time the voltage drops abruptly to its original value and remains at that value for one full engine cycle. The effect, then, is that a positive pulse occurs which occurs at a point well before the ignition of the second cylinder and which continues to a point following the ignition of the second cylinder. If this signal were derived from the voltage at the divider tips of a conventional ignition system, the pulse would begin at about the brushed position of the tips and continue until the next closed position of the tips is reached.

The voltage at the point H erescheint is amplified by any typical amplifier 246 and by a conductor 247 ^a n a resistor 248 is applied, which is connected between the gate electrode 252 and the ground of a triac. A capacitor 249 is connected in parallel with the resistor 248 and is used to form a shunt for any high-frequency transition voltages. The triac 252 is provided in a conventional form and has two anodes and two cathodes, which are parallel to one another.

7 09807/029? original inspected

- 50 -

of and opposite are connected to conduct in two directions when the correct voltage is applied to the gate electrode. The anodes and cathodes of triac 252 are connected to the ignition controller 16 connected so that when the triac 252 is conductive, the ignition control unit 16 does not interrupt the current through the primary winding 11 to generate a voltage pulse. As seen, one of the primary electrodes of triac 252 is through conductors 2533 and 76 connected to conductor 75, which, as mentioned above, is conductively connected to a terminal of the ignition control unit and the primary winding. The other primary dielectric electrode of the triac is with the Connected to ground at 250. As explained above, it is always when a voltage is applied to the gate electrode of triac 252, the triac on to disable the ignition controller and thus preventing the application of a clamping ring to the ignition device, which would normally be electrified at that time.

Referring again to the ring counter 40 and the voltage H passed by the .Closing of the switch tongue 55 arises, it can be seen that then, when the pulse of voltage H occurs, a voltage is applied through amplifier 246 and conductor 247 to the gate of triac 252, to make the triac conductive and to disable the ignition control unit. The effect of this is where it is assumed that the Switch 55 is the one that is closed xsö that for a period of time before the time at which the Fr. 2 cylinder igniter would normally would be energized, and further after the time the igniter would normally be energized, the Ignition control unit disabled. It is now possible by observing the effect of the engine speed under by observing a Tachometers or a display on a dynamometer or whatever other suitable device to determine what effect, if any, the disabling of the ignition device for the cylinder Fr. 2 has on the power of the engine. If the engine output is relatively remains unaffected, it can be seen without further ado that the cylinder Fr. 2 is not working properly, namely because of a faulty ignition

- 51 -

7 09807/023 7

direction of the vein for mechanical reasons. If what usually the ! "" all, the engine speed or the Ilotora output drops during the Cylinder Fr. 2 is set out of puncture, the person who is the Performs diagnosis, known that the cylinder ITr. 2 not the source of interference is.

While only one switch 55 is shown closed, it will be understood that any other switch can be closed whenever it is desirable to test any other cylinder. In practice, the switches 54 "^ ⁸ 59 are closed successively in order to observe the effect of a disabling function of the ignition devices of the various cylinders of the engine In any event, it can be seen that the expression occurs well before the time that voltage is normally applied to the igniter or igniters that are being disengaged, so there is no likelihood of any the igniter is partially affected before it is put out of puncture.

PJs is now referred to resetting the ring counter from a signal taken that is obtained when the last cylinder is in a state is located where the ignition device is just before ignition, so that the ring counter acts as a real ring counter by standing, dig repeats his game. Remember, this happened to you Signal derived from either terminal 52 or 53, depending on whether the engine to be tested is a four-cylinder or a six-cylinder engine is. In addition to this reset signal, it is desirable to to have a signal to ensure that the ring counter is on the Time is set back to deetr a relevant cylinder in a State where its igniter is normally energized. The reason for this is that it is desirable to use the ring counter synchronized with the operation of the engine and always it is possible that the ring counter gets out of step. Polly it is desirable that one receives a signal that a relevant ignition device

•, - 32 -

709807/0207

control is assigned, normally the ignition device for the cylinder Fr. 1, · and to use this signal to ensure that öe £, (1 <-. rd & vorrichtang is energized. Bas problen is though, de.O the connection that leads from Zündkabel.zu the respective ignition device, \ z. can ~ rallel lead to other ignition cables and a certain kapazitetive ode? j inductive pick the cable the I call device can be made, cd .'- srfol ₀ b, if other spark plugs or ignition devices are energized. This can lead to incorrect resetting of the counter. The invention provides means for safeguarding that the jerks from the selected candle will be disabled, except for a short period of time during which voltage is applied to the igniter for the selected candle .

Referring to the drawings and particularly to Pig. 1B encloses the clamp connector 2oO the ignition cable that goes from the candle 3C to the associated Distribution port 26 leads. The candle 30 is the candle "ITr. 1" insofar as as this is the first in an ignition sequence to have an ignition voltage receives. The Yerbinder 2o0 is preferably an inductive conductor ? form in which a voltage is induced in a coil, every time when an ignition voltage is applied to the plug 30. This Voltage pulse is in waveform I in JEag. 2 shown. I "s is to be noted that there is a first peak voltage followed by one oscillatory discharge. This voltage is represented by a Vidersts, nd 261 and a parallel capacitor 262 for the input of an amplifier 264 headed. The "effect of capacitor 262" is to reduce the voltage pulse to sharpen, which is taken up by the connector 2bO. The function of the Resistance 261 is the signal received by the pickup attenuate before applying it to amplifier 264. The amplifier 264 is primarily intended for impedance matching, and it is with his Power connection connected by conductor 266 to a +1 ^ volt source. Sr also has a ground connection that connects to the cash register at 265 is. The output of the amplifier 264 is applied through a resistor 267 to the control electrode of a transistor 268 whose> transmission electrodes and collector circuit in series with a resistor 269 and the

- όϊ -

709S07 / 029 7

ORIGINAL BATHROOM

: ■ ._- ■■ -: ■ - - 53 -

Lüiiiissionelectroden-Köllektorkkreis of a second transistor 27O between the + 15- "VolV> aelle and mass" are connected at 27I. Both transistors

268 and 27O are n-p-n transistors. When transistor 27O is conducting, it is conducting a voltage pulse that is received by tap 2oO and through the / Amplifier 264 is transmitted, for applying the positive voltage to the control electrode of transistor 263 to turn on transistor 263 and a Siromflu3 from the +15 volt 8troiricjuelle through the "resistor."

269 "and the collector emitting electrode paths of transistors 268 and 2J0- to Hasse. Bas results in a voltage drop across resistor 26n in the form of a sharp negative pulse shown in waveform J in FIG passed through diode 27I to a resistor 272 connected between the +15 Voit source and ground in series with a capacitor 273. The voltage on capacitor 273 is applied to the input terminal 276 of a linear, integrated timer circuit 275 * this timer circuit may be provided in one embodiment, the integrated as a 555 ^e ^ circuit is vertirben, and is so connected that it vibrator'arbeitet as a monostable multi. this is one of the usual ways, such as a. 555 ^he can be connected to an integrated circuit. the Stromanschuß 280 of this amplifier 275 is connected to the + 15-volt power source, and the control voltage terminal is connected via a condensate sator 279 a * ¹ ground connected. The threshold and SntladeanSchlüsse of the amplifier are connected together and, ai ^e i are connected in series between the Strömanschluß and ground to a junction between a capacitor 282 and the resistor 283 connected. The capacitor 282 and the resistor 283 form an RC circuit and determine the length of time during which the voltage appearing at the output terminal 277 remains after a trigger voltage has been applied to the input terminal 276. In other words, the capacitor 282 and the resistor 283 determine the duration of the flip-flap circuit of the multivibrator 275. The result is that a square wave pulse appears at the output terminal 277 which is initiated at the time a signal is received from the tap connector 260 and as a result of the application of an ignition voltage to the plug 30 and which ends at the end of the period of time which is determined by the capacitor 282 and the resistor 283. This impulse is as

. - ■■■■■.? ■. ■ - '. ".. - 34 -

7O98Q7 / O2§1

ORfGfNAL ■ 'INSPECTO) -

Pulse 28β with the waveform shown as K in FIG. 2. As can be seen, this pulse begins at the time the ignition pulse is picked up by connector 260. In other words, this pulse of waveform K begins at the same time as the ignition pulse and is initiated by the sharp negative peak of waveform J with the start of the ignition voltage applied to plug JO. The pulse 286, after being initiated by the pulse of shape J, remains present for a period of time which depends on the time constant of the monostable multivibrator. This pulse is applied through a conductor 285 »a resistor 287 imcL a capacitor 288 in parallel to a resistor 289, which in turn is connected between the control electrode and the emission electrode of an npn transistor 290. Capacitor 288 acts to differentiate the pulse from vdrd to create a sharp positive pulse which is applied to the control electrode of transistor 290. The transistor 290 is connected in series with the auxiliary srücks tell connection 43 cLes counter 40 via a conductor 291 and a resistor 5Ο8. As can be seen, the emission electrode of transistor 290 is connected at 292 to cash register. Whenever transistor 290 becomes conductive, the voltage at the reset terminal is reduced abruptly because there is a relatively low impedance path between this reset terminal and ground. This ensures that the sing counter is reset, regardless of whether the voltage is applied to the main trucks tellansehluß 42. In other words, the effect of picking up the signal from the cable to the candle Er. 1 after its modification by the transistor 268, the monostable multivibrator 275 »de & capacitor 288 and the associated circuit parts is to ensure that whenever an ignition voltage is applied to the ignition device 30, the ring counter is at the beginning of its game . In other words, if the ring counter gets out of step in any way, it will be restarted by the device described above.

As mentioned above, one of the difficulties is related having an arrangement as previously described in that the connection between connector 260 and amplifier 264 »

- 35 -

7 0 9807/0297 _{0RIG | NAL INSPECTED}

- 35 - ■■■ ... '■

which appears relatively short in the drawing, in the .Form of a relatively long Cable must be present so that the test device is connected to a can be conveniently located and a connection with the ignition cable is still possible, dias to the ignition device Ir. 2 leads. Because With this relatively long connection it is entirely possible that the cable picks up the signal from the ignition current that is sent to other ignition devices flows. This leads to an incorrect reset of the counter. Vie mentioned above, means are therefore provided in order to avoid this suspect that this should happen. "Furthermore, the arrangement is used becomes, as will become apparent below, even rla.nn effective, if .the device is paired with a motor that is running before power is turned on to the device. With certain known anoidizations the counter does not even start to perform the puncture, when the device is paired with a motor that runs before power is supplied has been switched on. Briefly, this function is achieved by preventing the signal from the ignition device ITr. 2 is transmitted to the reset terminal after the engine speed is ramping up, except during the time when an output signal from ITr level. 1 of the counter is available.

Returning to the circuit parts described above It will be remembered that the operation of transistor 268 is different from that depends on transistor 27O conducting. In other words, the "Ώηχε-sion electrode collector circuit" of the transistor 27Ο is in series with the The emission electrode collector circuit of the transistor 268 is switched, and except when transistor 270 conducts, no current can flow through the emission electrode collector circuit of transistor 268 and then no current can flow through resistor 269. So that a signal from the connector 26'0 to the Multivibrator 275 is transmitted, it is therefore necessary that the " Transistor 270 conducts. These circuits are described below.

If the engine is not running, power will flow from a +15 VoIt power source through the collector anission electrode circuit of an n-p-n transistor 295, and a resistor 293 to ground. A capacitor 294 is in parallel with the

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7 09807/0297 '

Resistor 293 is connected and acts as a filter capacitor, ir.i any Eochfreu-enzimpuls in the shunt pass to arsenic. Tic Cparming GXi ViCi-.rz; .ci ~ o. 29J vii-i! cn dir f expensive-l ^ -croö ^ öc-ε "'rT-sis-torc ?? G duroh sine diode 296, a conductor Γ97, a v / icierRttJnc ¹ Γ. ^ Γ-, cn: · a ^c _n conductor ÜJ9 applied. V "4.Ms the engine is running, the! Dr-: η ei 3 tor ^ 5 is kept conductive, and two.r by a connection with a resistor- χΐ a wash the + i ^ -Volt-r. troucuellc-- imc ". of the control electrode de ε Irf'.r-ßistcrs. bc" soon, however, oils JiouOj.di-cba0. will be.

A resistor JC-2 and a capacitor JCJ are connected between the output connection 'i 27? "Of the integrated Zeitge-Taers 275 ^ n ^ - cash register. Every time a pulse 2Bo aia Au3gant; scjascklu. .? IC (?., see "T. elienfom in 3 ig 2) is generated, current passes through the, -. esistance ₁ J Qi and the capacitor 503. the result is that for every cycle of IZotors dex * capacitor further comprising a 3ate is charged, which partly depends on the EZoit constant of the circuit, which is formed by the resistor JC2 and the capacitor JO? The bottom or positive connection of the capacitor 303 is via a conductor JCA with aeia not invortiex -ena j ' connected to the input connection of an amplifier 305 which, like the amplifiers 2CJ, 217, 225 and 23c, is a punlctionsv or stronger of the T ^ e uA741. The power connections of the amplifier are connected to +15 volts and -15 volt currents. " ! in capacitor 306 is connected between the +15 Tolt StronHjiifcllo and irs.cse. Correspondingly, a capacitor 307 is connected between the otroniane-chluj ";, which is connected to a -15-volt power supply, and the cash register. These capacitors are intended to eliminate any possible unwanted signals that may arise due to connections with above. e, n acrcn · - sources can arise. I? in feedback resistor 305 is connected between the output connection of amplifier 305 ^{and the} socket in J.leihe nit a resistor 309. The connection between the resistors ^ 1C and 309 is connected to the inverting " .input connector of the amplifier connected. The gain factor of the amplifier is determined by the ratio between the values of the resistors 3IO and 309.

Ss is a relatively high impedance discharge path for dtn capacitor 303 through

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709 8 07/0297

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resistor 502, conductor 23 5 and the internal connections between the output terminal 277 of the timer 275 and the ground connection 278 available. The capacitor 305 is therefore normally kept discharged. With the increase in the speed of the motor with a concomitant increase in the frequency of the pulses applied to the capacitor 505 286, the voltage on capacitor 305 rises to the point where the output voltage of the amplifier, 305 reaches its maximum value. Kit others: * / locate, the amplifier 505 is saturated.

The output of the amplifier 505 is connected through a resistor 3II to a Resistor 512-applied, which in turn is between the control electrode and the! emission electrode of an n-p-n transistor 5 "! 5 is connected. As soon as the output of amplifier 505 is above a relevant value as As a result of the increase in a setpoint value due to the speed of the motor, becomes the voltage across resistor 512 and thus between the control electrode and the emission electrode of the transistor 3 ^ 5 sufficiently high, to make the transistor 315 conductive. cause. This in turn causes the control electrode of transistor 295 to be connected to ground through the collector emission electrode path of transistor 315 · Bas causes the transistor 295 * to be switched off so that no further current flow occurs through it and through resistor 295 to ground. The result is that there is no longer any voltage at the resistor 295, through the diode 296, the conductor 297, the resistor 293 to the control electrode of transistor 270 could be applied. The transistor 270 thus becomes non-conductive, and because it is connected in series with transistor 268 is, it is no longer possible that the amplified pulse from the ignition cable of the ignition device 30 to the input of the timer. 275 is applied, and hence no signal is output from the output terminal 277 of the Timer 275 through resistor 2879, capacitor 288 and the Transistor 290 is supplied to reset terminal 43 of counter 40.

However, if the output voltage appears at stage 1, ie before the time the igniter _{would fire ITr 0} 1, the output voltage from stage 1 is passed through conductor 520, diode 521, conductor 297 and resistor 298. the conductor 299 to the control electrode

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709 807/029? ^^ _WSPE0 TE <>

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of transistor 270 is applied in order to "cause it to conduct again. This conductive state only prevails while an output from stage 1 is present. The output pulse from stage 1 is in the ¥ ellenformni Ii through the pulse 523 ... shown in Figure 2. As zv is seen, this pulse starts substantially before the Zündiiiipul s T1 of the waveform a, and he continues up to an intermediate point corresponding to the point a of the waveform D in other;.., ^r locations, the pulse J20 continues substantially for the farmer a Hall period, the center of the pulse is substantially aligned with the start of the ignition pulse. This pulse is, which, as mentioned above ,. through diode 321 and resistor 298 is applied to the control electrode of the transistor 27O in order to make it conductive again and the application of the voltage pulse which has been picked up by the connector 260 which is clamped around the ignition cable leading to the ignition device 50 to enable the reset port. The voltage applied to the control electrode of the transistor 270 from the output stage 1 of the counter 40 is shown in the waveform Ή in FIG. As can be seen, this waveform is the same in duration, but with a lower amplitude due to the fact that the voltage appears between the control electrode and the emission electrode of transistor 270, which are now conductive. The voltage drop, is thus substantially reduced, and the size of pulse 329 of waveform IT becomes much smaller than that of pulse 328 of waveform M.

the moment on the waveform L in 3? ig. 2 coming back, hesitant this waveform represents the pulse actually delivered to the reset terminal 43 is created. Ss is a negative pulse 327 of somewhat low amplitude present, and this pulse occurs due to the fact that the voltage on terminal 43 during the reset period due to the internal Circuitry of the counter 40 is reduced. About the Middle of the pulse 3 ^ 7 carries the pulse from the output of the timer 275 iind derives from the differentiation by the capacitor 288, to one sharp negative impulse 326, which is the impulse that actually does the Restoring effect executes. This pulse can only appear during the time there is an output on the output terminal of stage 1 of the Counter occurs. At least such an output pulse can only occur during

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ORIGINAL! MSPECTED

this time appear after the engine has ramped up at its speed. Prior to the time the Kotor is powered up, transistor 270 is held conductive due to this drop across resistor 295, which results from current flowing from the +15 volt power source through transistor 295 and resistor 293 " However, the engine is started up, this transistor is rendered non-conductive, as described above, and only when an output is received from the first stage of the counter 40, the transistor 2JO is conductive and thus in a state in which the dated Ignition cable to igniter 30 receiving signal can be transmitted through circuit to reset port 43. At all other times, any signal that may be picked up on connection to connector 260 is substantially blocked so that it does not pass through to reset port During the duration of the pulse 528 of the waveform IT, a reset signal derived from the connection of the label to the ignition device 30 can be transmitted et will be transmitted to the reset terminal.

It should also be noted that, unlike known device intended for this purpose, the device according to the invention works even when it is coupled to a motor that runs before the power supply to the device has been switched on. This is true because even if pulses are periodically received from the conductor ^{leading to the ignition device? - n} , the output of amplifier JO5 does not immediately rise to a v / ert to turn on transistor 315 and thus turn off transistor 295. This is the result of the fact that it takes a number of pulses to be derived from connector 2βθ, regardless of the hotord speed, so that capacitor 303 is sufficiently charged ^to saturate amplifier 305. The Hn signal is also applied for a short time from resistor 293 through diode 296 to keep transistor 270 on. The result is that the pulse received from connector 20O becomes so effective when an ignition voltage is applied to the ignition device that a voltage is applied to reset terminal 43 to increment the counter, and then the device operates as described above to increase the voltage pulse received from the lead to igniter 30

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BATH ORIGINAL

'to be transmitted by Ms to the meter only during the time during which the output voltage appears at the first stage of the selector.

From the foregoing it can be seen that a Magnose device is provided with which it is possible. is a voltage with the same frequency as that of the firing pulses, even if it is impossible to connect; to make to the distributor tips, as happened in the "past" is. This happens through the spontaneous generation of a square wave voltage with eggs Frequency of appearance of the ignition pulses, the gate direction being independent of the speed of the motor works to produce a pronounced voltage change to deliver between the appearances of impulses of sin. For the reason of this generated voltage with the same frequency as that of the ignition pulses, it is possible at the end of each half cycle of the generated in this way Voltage appearing voltage change to use to a test process to be initiated, which should begin before the appearance of a relevant ignition pulse.

As can also be seen, it is when a ring counter is below the Control of the generated voltage used v / M, which has been referred to above, is possible with the circuit according to the invention, this Reset ring counter by means of a signal that accompanies the ignition of a relevant ignition device, while ensuring that external signals, which are picked up at the connection to the ignition cable for this one ignition device have no effect on the resetting of the counter except during the time when the ignition pulse is normally applied to the ignition device concerned.

Expectations

709807/0297 BAD original

Claims (6)

Γ1 .) Analysis device for cylinder internal combustion engines with an electrical ignition device for each cylinder and with means for applying ignition voltage pulses in a sequence to the ignition devices, characterized by first means in connection with the source of the ignition pulses for generating a first periodically changing voltage a frequency of half the frequency of vision of the pulses, each half cycle of the voltage beginning essentially at the time of occurrence of one of the pulses and ending essentially at the time of the next of the pulses, second means in connection with the output of the "first means for generating a second periodically changing voltage from the first periodically changing voltage with a frequency which is twice that of the first voltage, such that a complete period of the second voltage appears between two such voltage pulses, such that the "inde of the first half-period is in the wes Occurring in the middle between two such voltage pulses, and means for initiating a test process in the vicinity of the ..indes of a first half cycle of the second periodically changing voltage, such that the test process is initiated at a time between the times at which successive voltage pulses occur. 2. Analysis device according to claim 1, characterized by "net, that both the first and the second change periodically Voltage are pike-corner wave voltages. 3 · Inalysis device according to claim 2, characterized in that the second means means for integrating the first square wave voltage to form a first triangular wave voltage with the frequency of the first hexagonal wave voltage, an inverter for inverting parts of the first triangular wave voltage to form A triangular wave voltage having twice the frequency of the first triangular wave voltage and means for converting the second triangular wave voltage into a second rectangular wave voltage having the frequency of the second triangular wave voltage. ■ 50 166 : ■■ ": -"
Wa / Ti. ■■ - - 2 - 709807/0 29 7 ORiQlNAL INSPECTED 4. Analysis device according to claim 1, characterized in that that an electronic counter is used in the test process, which at the end of each such first half period of the square wave voltage is advanced. 5. Analysis device according to claim 4 »characterized in that that means to the application of an ignition voltage pulse one of the ignition devices for generating a further voltage pulse always respond when such an ignition pulse is applied to the said ignition device, means to the further voltage pulses respond to control the counter in such a way that it is ensured that it is reset if one of the further pulses is generated, and means controlled by the counter prevent the generation of further pulses, except when the counter is in a counting stage, which corresponds to the time at which an ignition pulse is normally applied to the one ignition device. 6. Analysis device according to claim 1, characterized in that that the test device is a cathode ray tube with a screen, means for generating a substantially horizontal track the screen every time! when a voltage pulse is applied to one of the ignition devices is applied, and means for initiating the horizontal track at the end of a first half period of the second periodically changing Has tension. 709807/0 297